///*
// *
// * Copyright 2015, Google Inc.
// * All rights reserved.
// *
// * Redistribution and use in source and binary forms, with or without
// * modification, are permitted provided that the following conditions are
// * met:
// *
// *     * Redistributions of source code must retain the above copyright
// * notice, this list of conditions and the following disclaimer.
// *     * Redistributions in binary form must reproduce the above
// * copyright notice, this list of conditions and the following disclaimer
// * in the documentation and/or other materials provided with the
// * distribution.
// *     * Neither the name of Google Inc. nor the names of its
// * contributors may be used to endorse or promote products derived from
// * this software without specific prior written permission.
// *
// * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// *
// */
//
//#include <iostream>
//#include <memory>
//#include <string>
//
//#include <grpc++/grpc++.h>
//#include <thread>
//
//#include "helloworld.grpc.pb.h"
//
//using grpc::Channel;
//using grpc::ClientAsyncResponseReader;
//using grpc::ClientContext;
//using grpc::CompletionQueue;
//using grpc::Status;
//using helloworld::HelloRequest;
//using helloworld::HelloReply;
//using helloworld::Greeter;
//
//class GreeterClient {
//  public:
//    explicit GreeterClient(std::shared_ptr<Channel> channel)
//            : stub_(Greeter::NewStub(channel)) {}
//
//    // Assembles the client's payload and sends it to the server.
//    void SayHello(const std::string& user) {
//        // Data we are sending to the server.
//        HelloRequest request;
//        request.set_name(user);
//
//        // Call object to store rpc data
//        AsyncClientCall* call = new AsyncClientCall;
//
//        // stub_->AsyncSayHello() performs the RPC call, returning an instance to
//        // store in "call". Because we are using the asynchronous API, we need to
//        // hold on to the "call" instance in order to get updates on the ongoing RPC.
//        call->response_reader = stub_->AsyncSayHello(&call->context, request, &cq_);
//
//
//        // Request that, upon completion of the RPC, "reply" be updated with the
//        // server's response; "status" with the indication of whether the operation
//        // was successful. Tag the request with the memory address of the call object.
//        call->response_reader->Finish(&call->reply, &call->status, (void*)call);
//
//    }
//
//    // Loop while listening for completed responses.
//    // Prints out the response from the server.
//    void AsyncCompleteRpc() {
//        void* got_tag;
//        bool ok = false;
//
//        // Block until the next result is available in the completion queue "cq".
//        while (cq_.Next(&got_tag, &ok)) {
//            // The tag in this example is the memory location of the call object
//            AsyncClientCall* call = static_cast<AsyncClientCall*>(got_tag);
//
//            // Verify that the request was completed successfully. Note that "ok"
//            // corresponds solely to the request for updates introduced by Finish().
//            GPR_ASSERT(ok);
//
//            if (call->status.ok())
//                std::cout << "Greeter received: " << call->reply.message() << std::endl;
//            else
//                std::cout << "RPC failed" << std::endl;
//
//            // Once we're complete, deallocate the call object.
//            delete call;
//        }
//    }
//
//  private:
//
//    // struct for keeping state and data information
//    struct AsyncClientCall {
//        // Container for the data we expect from the server.
//        HelloReply reply;
//
//        // Context for the client. It could be used to convey extra information to
//        // the server and/or tweak certain RPC behaviors.
//        ClientContext context;
//
//        // Storage for the status of the RPC upon completion.
//        Status status;
//
//
//        std::unique_ptr<ClientAsyncResponseReader<HelloReply>> response_reader;
//    };
//
//    // Out of the passed in Channel comes the stub, stored here, our view of the
//    // server's exposed services.
//    std::unique_ptr<Greeter::Stub> stub_;
//
//    // The producer-consumer queue we use to communicate asynchronously with the
//    // gRPC runtime.
//    CompletionQueue cq_;
//};
//
//int main(int argc, char** argv) {
//
//
//    // Instantiate the client. It requires a channel, out of which the actual RPCs
//    // are created. This channel models a connection to an endpoint (in this case,
//    // localhost at port 50051). We indicate that the channel isn't authenticated
//    // (use of InsecureChannelCredentials()).
//    GreeterClient greeter(grpc::CreateChannel(
//            "localhost:50051", grpc::InsecureChannelCredentials()));
//
//    // Spawn reader thread that loops indefinitely
//    std::thread thread_ = std::thread(&GreeterClient::AsyncCompleteRpc, &greeter);
//
//    for (int i = 0; i < 100; i++) {
//        std::string user("world " + std::to_string(i));
//        greeter.SayHello(user);  // The actual RPC call!
//    }
//
//    std::cout << "Press control-c to quit" << std::endl << std::endl;
//    thread_.join();  //blocks forever
//
//    return 0;
//}
